I have looked all over the forums to see if I can avoid posting a simple question but I can't find a good answer to how I can tell if my car is running lean or rich? I have an 03 G35 Coupe with 64k miles on it, Motordyne Shockwave TDX2 catback, 5/16ths Intake manifold spacer and an injen CAI. I see a lot of people posting that their cars are running lean with similar mods, how do I tell? Thanks

 

You can't tell without adding an air/fuel gauge. However, you've added nothing that would make your car run rich (ie more fuel) so if anything you will be on the leaner side (ie more air) but with your mods you're probably not far off of the stock air/fuel ratio.

 

ok. I figured there was a quick response to that question. I have just started to put mods on the vehicle this summer and really don't want to cause any problems from lack of knowledge on secondary effects certain mods have. Thanks a lot!

 

No problem. At some point you may consider getting a tune if you add more mods because you will get leaner the more bolt one you do. Plus you can gain probably 20whp with a tune if you have most bolt ons.

 

right, I have been looking to do the Osiris tune, found a shop near me that is certified and seems to be a reputable place to get it done. I want to get ART test pipes before I do that though. Thanks for the tips

 

As already stated you are likely on the lean side, but you should be fine as long as the car is well taken car of. As far as an Osiris tune, I HIGHLY recommend it once you've completed all your performance mods, but try to find a shop who does a lot of them, not just one that is "authorized" to do one, VQ oriented shops will generally provide a much better tune.

Let me know if I can ever help you with anything!

-Rob